x86: rename pat_wc_enabled to pat_enabled

BTW, what does pat_wc_enabled stand for? Does it mean
"write-combining"?

Currently it is used to globally switch on or off PAT support.
Thus I renamed it to pat_enabled.
I think this increases readability (and hope that I didn't miss
something).

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 60bcb5b..6916fe4 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -805,7 +805,7 @@
 
 int set_memory_wc(unsigned long addr, int numpages)
 {
-	if (!pat_wc_enabled)
+	if (!pat_enabled)
 		return set_memory_uc(addr, numpages);
 
 	if (reserve_memtype(addr, addr + numpages * PAGE_SIZE,