tree-wide: drop assignments to r when we only need errno

If the whole call is simple and we don't need to look at the return value
apart from the conditional, let's use a form without assignment of the return
value. When the function call is more complicated, it still makes sense to
use a temporary variable.

src/core/socket.c

@@ -526,8 +526,7 @@ int socket_acquire_peer(Socket *s, int fd, SocketPeer **p) {
         assert(fd >= 0);
         assert(s);
 
-        r = getpeername(fd, &sa.peer.sa, &salen);
-        if (r < 0)
+        if (getpeername(fd, &sa.peer.sa, &salen) < 0)
                 return log_unit_error_errno(UNIT(s), errno, "getpeername failed: %m");
 
         if (!IN_SET(sa.peer.sa.sa_family, AF_INET, AF_INET6, AF_VSOCK)) {

src/shared/udev-util.c

@@ -118,12 +118,13 @@ static int device_new_from_dev_path(const char *devlink, sd_device **ret_device)
 
         assert(devlink);
 
-        r = stat(devlink, &st);
-        if (r < 0)
-                return log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_ERR, errno, "Failed to stat() %s: %m", devlink);
+        if (stat(devlink, &st) < 0)
+                return log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_ERR, errno,
+                                      "Failed to stat() %s: %m", devlink);
 
         if (!S_ISBLK(st.st_mode))
-                return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK), "%s does not point to a block device: %m", devlink);
+                return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK),
+                                       "%s does not point to a block device: %m", devlink);
 
         r = sd_device_new_from_devnum(ret_device, 'b', st.st_rdev);
         if (r < 0)

src/udev/udev-builtin-keyboard.c

@@ -110,10 +110,8 @@ static const char* parse_token(const char *current, int32_t *val_out) {
 static int override_abs(sd_device *dev, int fd, unsigned evcode, const char *value) {
         struct input_absinfo absinfo;
         const char *next;
-        int r;
 
-        r = ioctl(fd, EVIOCGABS(evcode), &absinfo);
-        if (r < 0)
+        if (ioctl(fd, EVIOCGABS(evcode), &absinfo) < 0)
                 return log_device_error_errno(dev, errno, "Failed to call EVIOCGABS");
 
         next = parse_token(value, &absinfo.minimum);
@@ -122,12 +120,12 @@ static int override_abs(sd_device *dev, int fd, unsigned evcode, const char *val
         next = parse_token(next, &absinfo.fuzz);
         next = parse_token(next, &absinfo.flat);
         if (!next)
-                return log_device_error_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Failed to parse EV_ABS override '%s'", value);
+                return log_device_error_errno(dev, SYNTHETIC_ERRNO(EINVAL),
+                                              "Failed to parse EV_ABS override '%s'", value);
 
         log_device_debug(dev, "keyboard: %x overridden with %"PRIi32"/%"PRIi32"/%"PRIi32"/%"PRIi32"/%"PRIi32,
                          evcode, absinfo.minimum, absinfo.maximum, absinfo.resolution, absinfo.fuzz, absinfo.flat);
-        r = ioctl(fd, EVIOCSABS(evcode), &absinfo);
-        if (r < 0)
+        if (ioctl(fd, EVIOCSABS(evcode), &absinfo) < 0)
                 return log_device_error_errno(dev, errno, "Failed to call EVIOCSABS");
 
         return 0;