PM: wakeup: Delete space in the end of string shown by pm_show_wakelocks()

pm_show_wakelocks() is called to generate a string when showing
attributes /sys/power/wake_(lock|unlock), but the string ends
with an unwanted space that was added back by mistake by commit
c9d967b ("PM: wakeup: simplify the output logic of
pm_show_wakelocks()").

Remove the unwanted space.

Fixes: c9d967b ("PM: wakeup: simplify the output logic of pm_show_wakelocks()")
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://patch.msgid.link/20250505-fix_power-v1-1-0f7f2c2f338c@quicinc.com
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Zijun Hu

kernel/power/wakelock.c

@@ -49,6 +49,9 @@ ssize_t pm_show_wakelocks(char *buf, bool show_active)
 			len += sysfs_emit_at(buf, len, "%s ", wl->name);
 	}
 
+	if (len > 0)
+		--len;
+
 	len += sysfs_emit_at(buf, len, "\n");
 
 	mutex_unlock(&wakelocks_lock);