FIR: Convert couple of methods to block-body

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/coneDiagnosticToFirDiagnostic.kt

@@ -163,11 +163,12 @@ private fun mapSystemHasContradictionError(
     diagnostic: ConeConstraintSystemHasContradiction,
     source: FirSourceElement,
     qualifiedAccessSource: FirSourceElement?,
-): List<FirDiagnostic<FirSourceElement>> = buildList<FirDiagnostic<FirSourceElement>> {
+): List<FirDiagnostic<FirSourceElement>> {
+    return buildList<FirDiagnostic<FirSourceElement>> {
         for (error in diagnostic.candidate.system.errors) {
             addIfNotNull(error.toDiagnostic(source, qualifiedAccessSource, diagnostic.candidate.callInfo.session.typeContext))
         }
-}.ifEmpty {
+    }.ifEmpty {
         listOfNotNull(
             diagnostic.candidate.system.errors.firstNotNullOfOrNull {
                 val message = when (it) {
@@ -179,13 +180,15 @@ private fun mapSystemHasContradictionError(
                 FirErrors.NEW_INFERENCE_ERROR.on(qualifiedAccessSource ?: source, message)
             }
         )
+    }
 }
 
 private fun ConstraintSystemError.toDiagnostic(
     source: FirSourceElement,
     qualifiedAccessSource: FirSourceElement?,
     typeContext: ConeTypeContext,
-): FirDiagnostic<FirSourceElement>? = when (this) {
+): FirDiagnostic<FirSourceElement>? {
+    return when (this) {
         is NewConstraintError -> {
             val position = position.from
             val argument =
@@ -223,6 +226,7 @@ private fun ConstraintSystemError.toDiagnostic(
             }
         }
         else -> null
+    }
 }
 
 private val NewConstraintError.lowerConeType: ConeKotlinType get() = lowerType as ConeKotlinType