[flang] Fix portability warning that was incorrectly an "else if"

[klausler]

Summary

A semantics check for an assumed-length dummy procedure pointer was
inappropriately part of an "else" clause for a preceding check,
causing it to not be applied in all situations.

[clementval]

LGTM

flang/lib/Semantics/check-declarations.cpp

     if (const Symbol *result{FindFunctionResult(symbol)}) {
       if (IsPointer(*result)) {
         messages_.Say(
             "An assumed-length CHARACTER(*) function cannot return a POINTER"_err_en_US);
       }
-    } else if (IsProcedurePointer(symbol) && IsDummy(symbol)) {
+    }
+    if (IsProcedurePointer(symbol) && IsDummy(symbol)) {
       messages_.Say(
           "A dummy procedure pointer should not have assumed-length CHARACTER(*) result type"_port_en_US);
       // The non-dummy case is a hard error that's caught elsewhere.
     }
   }

flang/test/Semantics/call01.f90

     !ERROR: Assumed-length character function must be defined with a length to be called
     nested = f14(n-1) ! 15.6.2.1(3)
   end function nested
 end function
 
-subroutine s01(f1, f2, fp1, fp2)
+subroutine s01(f1, f2, fp1, fp2, fp3)
   !PORTABILITY: A dummy procedure pointer should not have assumed-length CHARACTER(*) result type
   character*(*) :: f1, f3, fp1
   external :: f1, f3
-  pointer :: fp1
+  pointer :: fp1, fp3
   !PORTABILITY: A dummy procedure pointer should not have assumed-length CHARACTER(*) result type
   procedure(character*(*)), pointer :: fp2
   interface
     character*(*) function f2()
     end function
+    !PORTABILITY: A dummy procedure pointer should not have assumed-length CHARACTER(*) result type
+    character*(*) function fp3()
+    end function
     !ERROR: A function interface may not declare an assumed-length CHARACTER(*) result
     character*(*) function f4()
     end function
   end interface
   print *, f1()