atomic: Exclude the unsupported implementation headers from checkheaders

Signed-off-by: Martin Storsjö <martin@martin.st>

libavutil/Makefile

@@ -103,6 +103,10 @@ OBJS += $(COMPAT_OBJS:%=../compat/%)
 
 SKIPHEADERS          = old_pix_fmts.h
 
+SKIPHEADERS-$(HAVE_MACHINE_RW_BARRIER)          += atomic_suncc.h
+SKIPHEADERS-$(HAVE_MEMORYBARRIER)               += atomic_win32.h
+SKIPHEADERS-$(HAVE_SYNC_VAL_COMPARE_AND_SWAP)   += atomic_gcc.h
+
 TESTPROGS = adler32                                                     \
             aes                                                         \
             atomic                                                      \