Use macros for exit values

sway/main.c

@@ -90,7 +90,7 @@ int main(int argc, char **argv) {
 #else
 			fprintf(stdout, "version not detected\n");
 #endif
-			exit(0);
+			exit(EXIT_SUCCESS);
 			break;
 		case 'V': // verbose
 			verbose = 1;
@@ -98,10 +98,10 @@ int main(int argc, char **argv) {
 		case 'p': ; // --get-socketpath
 			if (getenv("SWAYSOCK")) {
 				fprintf(stdout, "%s\n", getenv("SWAYSOCK"));
-				exit(0);
+				exit(EXIT_SUCCESS);
 			} else {
 				fprintf(stderr, "sway socket not detected.\n");
-				exit(1);
+				exit(EXIT_FAILURE);
 			}
 			break;
 		}

swaybg/main.c

@@ -29,7 +29,7 @@ void sway_terminate(void) {
 	}
 	list_free(surfaces);
 	registry_teardown(registry);
-	exit(1);
+	exit(EXIT_FAILURE);
 }
 
 int main(int argc, const char **argv) {

swaygrab/main.c

@@ -10,7 +10,7 @@
 #include "ipc-client.h"
 
 void sway_terminate(void) {
-	exit(1);
+	exit(EXIT_FAILURE);
 }
 
 int numlen(int n) {
@@ -163,7 +163,7 @@ int main(int argc, char **argv) {
 #else
 			fprintf(stdout, "version not detected\n");
 #endif
-			exit(0);
+			exit(EXIT_SUCCESS);
 			break;
 		}
 	}

swaymsg/main.c

@@ -12,7 +12,7 @@
 #include "log.h"
 
 void sway_terminate(void) {
-	exit(1);
+	exit(EXIT_FAILURE);
 }
 
 int main(int argc, char **argv) {
@@ -52,7 +52,7 @@ int main(int argc, char **argv) {
 #else
 			fprintf(stdout, "version not detected\n");
 #endif
-			exit(0);
+			exit(EXIT_SUCCESS);
 			break;
 		}
 	}