lib/raid6: Fix filename emitted in generated code

The files were renamed in commit cc4589ebf; fix the name in the file
itself.

Signed-off-by: Dan McGee <dpmcgee@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

lib/raid6/int.uc

@@ -11,7 +11,7 @@
  * ----------------------------------------------------------------------- */
 
 /*
- * raid6int$#.c
+ * int$#.c
  *
  * $#-way unrolled portable integer math RAID-6 instruction set
  *