[mlir] Fix typos in comments in 1:N type conversion utils. (NFC)

[ingomueller-net]

Comment-only change: self-accepting...

mlir/include/mlir/Transforms/OneToNTypeConversion.h

 
 /// Base class for patterns with 1:N type conversions. Derived classes have to
 /// overwrite the `matchAndRewrite` overlaod that provides additional
 /// information for 1:N type conversions.
 class OneToNConversionPattern : public RewritePatternWithConverter {
 public:
   using RewritePatternWithConverter::RewritePatternWithConverter;
 
-  /// This function has to be implemented by base classes and is called from the
-  /// usual overloads. Like in "normal" `DialectConversion`, the function is
+  /// This function has to be implemented by derived classes and is called from
+  /// the usual overloads. Like in "normal" `DialectConversion`, the function is
   /// provided with the converted operands (which thus have target types). Since
-  /// 1:N conversion are supported, there is usually no 1:1 relationship between
-  /// the original and the converted operands. Instead, the provided
+  /// 1:N conversions are supported, there is usually no 1:1 relationship
+  /// between the original and the converted operands. Instead, the provided
   /// `operandMapping` can be used to access the converted operands that
   /// correspond to a particular original operand. Similarly, `resultMapping`
   /// is provided to help with assembling the result values, which may have 1:N
   /// correspondences as well. In that case, the original op should be replaced
   /// with the overload of `replaceOp` that takes the provided `resultMapping`
   /// in order to deal with the mapping of converted result values to their
   /// usages in the original types correctly.
   virtual LogicalResult matchAndRewrite(Operation *op,