xtensa: rearrange NMI exit path

NMI exit path to userspace should neither check TIF_DB_DISABLED nor call
check_tlb_sanity because NMI shouldn't touch anything related to
userspace. Drop kernel/userspace check in NMI exit path.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/kernel/entry.S

@@ -488,9 +488,10 @@ KABI_W	or	a3, a3, a2
 common_exception_return:
 
 #if XTENSA_FAKE_NMI
-	l32i	a2, a1, PT_EXCCAUSE
-	movi	a3, EXCCAUSE_MAPPED_NMI
-	beq	a2, a3, .LNMIexit
+	l32i	abi_tmp0, a1, PT_EXCCAUSE
+	movi	abi_tmp1, EXCCAUSE_MAPPED_NMI
+	l32i	abi_saved1, a1, PT_PS
+	beq	abi_tmp0, abi_tmp1, 4f
 #endif
 1:
 	irq_save a2, a3
@@ -550,12 +551,6 @@ common_exception_return:
 	j	4f
 #endif
 
-#if XTENSA_FAKE_NMI
-.LNMIexit:
-	l32i	abi_saved1, a1, PT_PS
-	_bbci.l	abi_saved1, PS_UM_BIT, 4f
-#endif
-
 5:
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	_bbci.l	a4, TIF_DB_DISABLED, 7f