Fix doxygen warnings

Change-Id: I7c3b685a5313f30e5d6cf20bc958e9876856a56d
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/51926
Auto-Submit: Ben Clayton <bclayton@google.com>
Commit-Queue: David Neto <dneto@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: David Neto <dneto@google.com>
diff --git a/src/reader/spirv/function.h b/src/reader/spirv/function.h
index d9d8384..4e316f4 100644
--- a/src/reader/spirv/function.h
+++ b/src/reader/spirv/function.h
@@ -851,9 +851,11 @@
   /// @returns the value itself, or converted to signed integral
   TypedExpression ToSignedIfUnsigned(TypedExpression value);
 
-  /// Returns true if the given SPIR-V id represents a constant float 0.
+  /// @param value_id the value identifier to check
+  /// @returns true if the given SPIR-V id represents a constant float 0.
   bool IsFloatZero(uint32_t value_id);
-  /// Returns true if the given SPIR-V id represents a constant float 1.
+  /// @param value_id the value identifier to check
+  /// @returns true if the given SPIR-V id represents a constant float 1.
   bool IsFloatOne(uint32_t value_id);
 
  private: