Simplify assertion

Author: catamorphism

icu4c/source/test/intltest/messageformat2test.cpp

@@ -276,8 +276,7 @@ void TestMessageFormat2::testHighLoneSurrogate() {
       .setPattern(loneSurrogate, pe, errorCode)
       .build(errorCode);
     UnicodeString result = msgfmt1.formatToString({}, errorCode);
-    assertEquals("testHighLoneSurrogate", U_MF_SYNTAX_ERROR, errorCode);
-    errorCode.reset();
+    errorCode.expectErrorAndReset(U_MF_SYNTAX_ERROR, "testHighLoneSurrogate");
 }
 
 // ICU-22890 lone surrogate cause infinity loop
@@ -291,8 +290,7 @@ void TestMessageFormat2::testLowLoneSurrogate() {
       .setPattern(loneSurrogate, pe, errorCode)
       .build(errorCode);
     UnicodeString result = msgfmt2.formatToString({}, errorCode);
-    assertEquals("testLowLoneSurrogate", U_MF_SYNTAX_ERROR, errorCode);
-    errorCode.reset();
+    errorCode.expectErrorAndReset(U_MF_SYNTAX_ERROR, "testLowLoneSurrogate");
 }
 
 void TestMessageFormat2::dataDrivenTests() {