Fix typo in the C API comments

llvm-svn: 258033
diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
index c8fda15..6899f07 100644
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -1200,7 +1200,7 @@
 void LLVMReplaceAllUsesWith(LLVMValueRef OldVal, LLVMValueRef NewVal);
 
 /**
- * Determine whether the specified constant instance is constant.
+ * Determine whether the specified value instance is constant.
  */
 LLVMBool LLVMIsConstant(LLVMValueRef Val);