Revert "Replace FLAC__CPU_X86_64 with FLaC__CPU_X86_64."

This reverts commit 151739921b74fbf31420358a5fbeb094efa017ed.

This patch only when part way to replace all FLAC_* with FLaC_*
and its really not worth going all the way.
diff --git a/src/libFLAC/stream_encoder_intrin_sse2.c b/src/libFLAC/stream_encoder_intrin_sse2.c
index b2303a4..bef5545 100644
--- a/src/libFLAC/stream_encoder_intrin_sse2.c
+++ b/src/libFLAC/stream_encoder_intrin_sse2.c
@@ -35,7 +35,7 @@
 #endif
 
 #ifndef FLAC__NO_ASM
-#if (defined FLAC__CPU_IA32 || defined FLaC__CPU_X86_64) && defined FLAC__HAS_X86INTRIN
+#if (defined FLAC__CPU_IA32 || defined FLAC__CPU_X86_64) && defined FLAC__HAS_X86INTRIN
 #include "private/stream_encoder.h"
 #ifdef FLAC__SSE2_SUPPORTED
 
@@ -154,5 +154,5 @@
 }
 
 #endif /* FLAC__SSE2_SUPPORTED */
-#endif /* (FLAC__CPU_IA32 || FLaC__CPU_X86_64) && FLAC__HAS_X86INTRIN */
+#endif /* (FLAC__CPU_IA32 || FLAC__CPU_X86_64) && FLAC__HAS_X86INTRIN */
 #endif /* FLAC__NO_ASM */