x86: use __ASSEMBLY__ rather than __ASSEMBLER__

As Ingo pointed out in a separate patch, we should be using __ASSEMBLY__.
Make that the case in pgtable headers.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
LKML-Reference: <20100605114042.35ac69c1@dev.queued.net>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

arch/x86/include/asm/pgtable_32_types.h

@@ -26,7 +26,7 @@
  */
 #define VMALLOC_OFFSET	(8 * 1024 * 1024)
 
-#ifndef __ASSEMBLER__
+#ifndef __ASSEMBLY__
 extern bool __vmalloc_start_set; /* set once high_memory is set */
 #endif