[NFC][llvm] Remove duplicate isUEFI check (#136593)

In `X86MCTargetDesc.cpp` while fixing the handling of UEFI target in the
`createX86MCAsmInfo` function (#132461), the previous incorrect handling
of isUEFI was not removed. This patch cleans up that case.

Author: Prabhuk

llvm/lib/Target/X86/MCTargetDesc/X86MCTargetDesc.cpp

@@ -452,8 +452,6 @@ static MCAsmInfo *createX86MCAsmInfo(const MCRegisterInfo &MRI,
   } else if (TheTriple.isOSCygMing() ||
              TheTriple.isWindowsItaniumEnvironment()) {
     MAI = new X86MCAsmInfoGNUCOFF(TheTriple);
-  } else if (TheTriple.isUEFI()) {
-    MAI = new X86MCAsmInfoGNUCOFF(TheTriple);
   } else {
     // The default is ELF.
     MAI = new X86ELFMCAsmInfo(TheTriple);