[PowerPC, test] Fix use of undef FileCheck var

[thopre]

Summary

Commit 6646033e6e759657b6122fde64844fd28a2c9635 removed the definition
of variable RESULT used in two CHECK-NOT directives in LLVM test
CodeGen/PowerPC/ppc64-i128-abi.ll. This commit replaces the uses by the
regex that was used to define that variable.

[nemanjai]

Ah yes, this should have been removed on the original commit. Thanks for fixing it. LGTM.

llvm/test/CodeGen/PowerPC/ppc64-i128-abi.ll

 ; CHECK-LE-LABEL: @v1i128_increment_by_val
 ; CHECK-LE-NOT: xxswapd
 ; CHECK-LE: adduqm 2, 2, 3
 ; CHECK-LE: blr
 
 ; CHECK-BE-LABEL: @v1i128_increment_by_val
 ; CHECK-BE-NOT: xxswapd {{[0-9]+}}, 34
 ; CHECK-BE-NOT: xxswapd {{[0-9]+}}, 35
-; CHECK-BE-NOT: xxswapd 34, [[RESULT]]
+; CHECK-BE-NOT: xxswapd 34, {{[0-9]+}}
 ; CHECK-BE: adduqm 2, 2, 3
 ; CHECK-BE: blr
 
 ; CHECK-NOVSX-LABEL: @v1i128_increment_by_val
-; CHECK-NOVSX-NOT: xxswapd 34, [[RESULT]]
+; CHECK-NOVSX-NOT: xxswapd 34, {{[0-9]+}}
 ; CHECK-NOVSX: adduqm 2, 2, 3
 ; CHECK-NOVSX: blr
 }
 
 ; Little Endian (VSX and VMX):
 ;   Lower 64-bits of %a are passed in register 3
 ;   Upper 64-bits of %a are passed in register 4
 ;   Increment lower 64-bits using addic (immediate value of 1)