fix rdmsrl() truncation bug

rdmsrl() shifts an unsigned long by 32 bits, which on x86_32 results in the data being discarded. patch fixes that by casting to __u64 before the shift.

diff -r 829517be689f xen/include/asm-x86/msr.h
@@ -12,7 +12,7 @@
       __asm__ __volatile__("rdmsr" \

			    : "=a" (a__), "=d" (b__) \
			    : "c" (msr)); \
-       val = a__ | (b__<<32); \
+       val = a__ | ((__u64)b__<<32); \

} while(0);

#define wrmsr(msr,val1,val2) \

error compiling committee.c: too many arguments to function