"Redundant suspend modifier": fix false negative with only recursive call

#KT-35829 Fixed

idea/testData/inspectionsLocal/redundantSuspend/recursiveCall.kt

@@ -0,0 +1,3 @@
+<caret>suspend fun foo() {
+    foo()
+}

idea/testData/inspectionsLocal/redundantSuspend/recursiveCall.kt.after

@@ -0,0 +1,3 @@
+fun foo() {
+    foo()
+}