Mixing fd-based and stream-base IO results in interleaved output like
following:

=====================================
liblockdep 4.7.6
-------------------------------------
conopal/372 is trying to release lock (0x3a45c) at:
/lib/libpt.so.2.17-alpha2(_ZN11PTimedMutex6SignalEv+0x3c) [0xb613c688]
but there are no more locks to release!
other info that might help us debug this:
no locks held by conopal/372.
stack backtrace:
=====================================
liblockdep 4.7.6
---------------------------------/usr/lib/liblockdep.so.4.7.6(+0x1e3c)[0xb67c2e3c]
/usr/lib/liblockdep.so.4.7.6(+0x5fe0)[0xb67c6fe0]
/usr/lib/liblockdep.so.4.7.6(+0x6450)[0xb67c7450]
/usr/lib/liblockdep.so.4.7.6(lock_release+0x5c)[0xb67c7c40]
/usr/lib/liblockdep.so.4.7.6(pthread_mutex_unlock+0x38)[0xb67c91d4]
/lib/libpt.so.2.17-alpha2(_ZN11PTimedMutex6SignalEv+0x3c)[0xb613c688]
/lib/libpt.so.2.17-alpha2(_ZN10PContainer14AssignContentsERKS_+0xe4)[0xb6160730]
/lib/libopal.so.3.17-alpha2(_ZN15OpalMediaFormat14AssignContentsERK10PContainer+0x90)[0xb6435edc]
/lib/libopal.so.3.17-alpha2(_ZN15OpalMediaFormataSERK7PString+0x68)[0xb643b610]
/lib/libopal.so.3.17-alpha2(_ZN15OpalMediaFormatC2EPKc+0x68)[0xb643b6cc]
/lib/libopal.so.3.17-alpha2(_ZN11OpalWAVFile14AddMediaFormatERK15OpalMediaFormat+0x330)[0xb66b2224]
/lib/libopal.so.3.17-alpha2(+0x2526f8)[0xb640c6f8]
/lib/ld-linux-armhf.so.3(+0x102f0)[0xb6f852f0]
/lib/ld-linux-armhf.so.3(+0x1044c)[0xb6f8544c]
/lib/ld-linux-armhf.so.3(+0xac4)[0xb6f75ac4]
/usr/lib/liblockdep.so.4.7.6(+0x1e3c)[0xb67c2e3c]
/usr/lib/liblockdep.so.4.7.6(+0x5fe0)[0xb67c6fe0]
/usr/lib/liblockdep.so.4.7.6(+0x6450)[0xb67c7450]
/usr/lib/liblockdep.so.4.7.6(lock_release+0x5c)[0xb67c7c40]
/usr/lib/liblockdep.so.4.7.6(pthread_mutex_unlock+0x38)[0xb67c91d4]
/lib/libpt.so.2.17-alpha2(_ZN11PTimedMutex6SignalEv+0x3c)[0xb613c688]
/lib/libopal.so.3.17-alpha2(_ZN15OpalMediaFormat14AssignContentsERK10PContainer+0x78)[0xb6435ec4]
/lib/libopal.so.3.17-alpha2(_ZN15OpalMediaFormataSERK7PString+0x68)[0xb643b610]
/lib/libopal.so.3.17-alpha2(_ZN15OpalMediaFormatC2EPKc+0x68)[0xb643b6cc]
/lib/libopal.so.3.17-alpha2(_ZN11OpalWAVFile14AddMediaFormatERK15OpalMediaFormat+0x330)[0xb66b2224]
/lib/libopal.so.3.17-alpha2(+0x2526f8)[0xb640c6f8]
/lib/ld-linux-armhf.so.3(+0x102f0)[0xb6f852f0]
/lib/ld-linux-armhf.so.3(+0x1044c)[0xb6f8544c]
/lib/ld-linux-armhf.so.3(+0xac4)[0xb6f75ac4]

Therefore change all bare printf(...) to dprintf(STDOUT_FILENO, ...) to
sychronize with backtrace_symbols_fd().

[ BUG: bad unlock balance detected! ]
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: a.p.zijlstra@chello.nl
Cc: ben@decadent.org.uk
Link: http://lkml.kernel.org/r/20170525130005.5947-12-alexander.levin@verizon.comSigned-off-by: Ingo Molnar <mingo@kernel.org>