powerpc/lib: Declare static methods

Functions do_stf_{entry,exit}_barrier_fixups are static but not declared as
such. This was detected by `sparse` tool with the following warning:

	arch/powerpc/lib/feature-fixups.c:121:6: warning: symbol 'do_stf_entry_barrier_fixups' was not declared. Should it be static?

	arch/powerpc/lib/feature-fixups.c:171:6: warning: symbol 'do_stf_exit_barrier_fixups' was not declared. Should it be static?

This patch declares both functions as static, as they are only called by
do_stf_barrier_fixups(), which is in the same source code file.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/lib/feature-fixups.c

@@ -118,7 +118,7 @@ void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
 }
 
 #ifdef CONFIG_PPC_BOOK3S_64
-void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
+static void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
 {
 	unsigned int instrs[3], *dest;
 	long *start, *end;
@@ -168,7 +168,7 @@ void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
 		                                           : "unknown");
 }
 
-void do_stf_exit_barrier_fixups(enum stf_barrier_type types)
+static void do_stf_exit_barrier_fixups(enum stf_barrier_type types)
 {
 	unsigned int instrs[6], *dest;
 	long *start, *end;