Fix typo in a comment added in r195455.

Credit to Matheus Almeida for spotting it.

llvm-svn: 195456

llvm/lib/Target/Mips/MipsSEISelLowering.cpp

@@ -2211,7 +2211,7 @@ SDValue MipsSETargetLowering::lowerBUILD_VECTOR(SDValue Op,
 
     // If the value fits into a simm10 then we can use ldi.[bhwd]
     // However, if it isn't an integer type we will have to bitcast from an
-    // integer type first. Also, it there are any undefs, we must lower them
+    // integer type first. Also, if there are any undefs, we must lower them
     // to defined values first.
     if (ResTy.isInteger() && !HasAnyUndefs && SplatValue.isSignedIntN(10))
       return Op;