feat: log disabling planes without line breaks

Enumerating all planes to be disabled makes the log unnecessary
sparse. Instead just list all planes in a single line.

For that introduce new API function to log something without line
break in the end and adapt the log callback function pointer.

BREAKING CHANGE: log callback function arguments change.

alloc.c

@@ -618,16 +618,17 @@ bool liftoff_output_apply(struct liftoff_output *output, drmModeAtomicReq *req)
 
 	/* Disable all planes. Do it before building mappings to make sure not
 	   to hit bandwidth limits because too many planes are enabled. */
+	liftoff_log_cnt(LIFTOFF_DEBUG, "Disabling planes:");
 	liftoff_list_for_each(plane, &device->planes, link) {
 		if (plane->layer == NULL) {
-			liftoff_log(LIFTOFF_DEBUG,
-				    "Disabling plane %"PRIu32, plane->id);
+			liftoff_log_cnt(LIFTOFF_DEBUG, " %"PRIu32, plane->id);
 			if (!plane_apply(plane, NULL, req, &compatible)) {
 				return false;
 			}
 			assert(compatible);
 		}
 	}
+	liftoff_log(LIFTOFF_DEBUG, "");
 
 	result.req = req;
 	result.planes_len = liftoff_list_length(&device->planes);

include/libliftoff.h

@@ -74,7 +74,7 @@ enum liftoff_log_importance {
 	LIFTOFF_DEBUG,
 };
 
-typedef void (*liftoff_log_func)(enum liftoff_log_importance importance,
+typedef void (*liftoff_log_func)(enum liftoff_log_importance importance, bool newline,
 				 const char *fmt, va_list args);
 
 void liftoff_log_init(enum liftoff_log_importance verbosity,

include/log.h

@@ -11,6 +11,8 @@
 
 void liftoff_log(enum liftoff_log_importance verbosity,
 		 const char *format, ...) _LIFTOFF_ATTRIB_PRINTF(2, 3);
+void liftoff_log_cnt(enum liftoff_log_importance verbosity,
+		 const char *format, ...) _LIFTOFF_ATTRIB_PRINTF(2, 3);
 void liftoff_log_errno(enum liftoff_log_importance verbosity, const char *msg);
 
 #endif

log.c

@@ -5,11 +5,13 @@
 
 static enum liftoff_log_importance log_importance = LIFTOFF_ERROR;
 
-static void log_stderr(enum liftoff_log_importance verbosity, const char *fmt,
+static void log_stderr(enum liftoff_log_importance verbosity, bool newline, const char *fmt,
 		       va_list args)
 {
 	vfprintf(stderr, fmt, args);
-	fprintf(stderr, "\n");
+	if (newline) {
+		fprintf(stderr, "\n");
+	}
 }
 
 static liftoff_log_func log_callback = log_stderr;
@@ -37,7 +39,19 @@ void liftoff_log(enum liftoff_log_importance verbosity, const char *fmt, ...)
 
 	va_list args;
 	va_start(args, fmt);
-	log_callback(verbosity, fmt, args);
+	log_callback(verbosity, true, fmt, args);
+	va_end(args);
+}
+
+void liftoff_log_cnt(enum liftoff_log_importance verbosity, const char *fmt, ...)
+{
+	if (!log_has(verbosity)) {
+		return;
+	}
+
+	va_list args;
+	va_start(args, fmt);
+	log_callback(verbosity, false, fmt, args);
 	va_end(args);
 }