fix nmi_watchdog=2 bootup hang

wrmsrl() is broken, dropping the upper 32bits of the value to be
written. This broke the NMI watchdog on AMD hardware. (and it
probably broke other code too.)
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/asm-i386/paravirt.h

@@ -539,7 +539,7 @@ static inline int paravirt_write_msr(unsigned msr, unsigned low, unsigned high)
 	val = paravirt_read_msr(msr, &_err);	\
 } while(0)
 
-#define wrmsrl(msr,val)		((void)paravirt_write_msr(msr, val, 0))
+#define wrmsrl(msr,val)		wrmsr(msr, (u32)((u64)(val)), ((u64)(val))>>32)
 #define wrmsr_safe(msr,a,b)	paravirt_write_msr(msr, a, b)
 
 /* rdmsr with exception handling */