fix(versal): fix Misra-C violations in bl31_setup and pm_svc_main

Fix some Misra-C violations. The similar fixes were done by commit
eb0d2b17722c ("fix(zynqmp): resolve misra R15.6 warnings") and commit
dd1fe7178b57 ("fix(zynqmp): resolve misra R14.4 warnings").

Signed-off-by: Michal Simek <michal.simek@amd.com>
Change-Id: I3ffa92724a09871f7f99c9ac6c326994c165e9bd
diff --git a/plat/xilinx/versal/bl31_versal_setup.c b/plat/xilinx/versal/bl31_versal_setup.c
index 349b856..9b36208 100644
--- a/plat/xilinx/versal/bl31_versal_setup.c
+++ b/plat/xilinx/versal/bl31_versal_setup.c
@@ -184,8 +184,9 @@
 		}
 	}
 
-	if (handler != NULL)
-		handler(intr_id, flags, handle, cookie);
+	if (handler != NULL) {
+		return handler(intr_id, flags, handle, cookie);
+	}
 
 	return 0;
 }