Fix a bug showing incorrect line number when a probe is put on the head of an
inline function. This patch updates find_perf_probe_point() and introduces new
rules to get correct line number.

 - If debuginfo doesn't have a correct file name, we shouldn't return line
   number too, because, without file name, line number is meaningless.

 - If the address is in a function, it stores the function name and the offset
   from the function entry.

   - If the address is on a line, it tries to get the relative line number from
     the function entry line, except for the address is same as the entry
     address of the function (in this case, the relative line number should
     be 0).

     - If the address is in an inline function entry (call-site), it uses the
       inline function call line number as the line on which the address is.

   - If the address is in an inline function body, it stores the inline
     function name and offset from the inline function call site instead of the
     (non-inlined) function.

Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110330092605.2132.11629.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>