powerpc/mce: Remove unused but set variable

Remove the unused but set variable srr1 in save_mce_event() to
fix the following GCC warning when building with 'W=1':

  arch/powerpc/kernel/mce.c:75:11: warning: variable 'srr1' set but not used

It has never been used.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/mce.c

@@ -72,7 +72,6 @@ void save_mce_event(struct pt_regs *regs, long handled,
 		    struct mce_error_info *mce_err,
 		    uint64_t nip, uint64_t addr)
 {
-	uint64_t srr1;
 	int index = __this_cpu_inc_return(mce_nest_count) - 1;
 	struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);
 
@@ -99,8 +98,6 @@ void save_mce_event(struct pt_regs *regs, long handled,
 		mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
 	mce->severity = MCE_SEV_ERROR_SYNC;
 
-	srr1 = regs->msr;
-
 	/*
 	 * Populate the mce error_type and type-specific error_type.
 	 */