Fix --lock-video-orientation syntax in help

Commit f76fe2c0d4 fixed README and tests.

Fix command line help and manpage.

app/scrcpy.1

@@ -83,7 +83,7 @@ Inject computer clipboard text as a sequence of key events on Ctrl+v (like MOD+S
 This is a workaround for some devices not behaving as expected when setting the device clipboard programmatically.
 
 .TP
-.BI "\-\-lock\-video\-orientation " [value]
+.BI "\-\-lock\-video\-orientation[=value]
 Lock video orientation to \fIvalue\fR. Possible values are "unlocked", "initial" (locked to the initial orientation), 0, 1, 2 and 3. Natural device orientation is 0, and each increment adds a 90 degrees otation counterclockwise.
 
 Default is "unlocked".

app/src/cli.c

@@ -79,7 +79,7 @@ scrcpy_print_usage(const char *arg0) {
         "        This is a workaround for some devices not behaving as\n"
         "        expected when setting the device clipboard programmatically.\n"
         "\n"
-        "    --lock-video-orientation [value]\n"
+        "    --lock-video-orientation[=value]\n"
         "        Lock video orientation to value.\n"
         "        Possible values are \"unlocked\", \"initial\" (locked to the\n"
         "        initial orientation), 0, 1, 2 and 3.\n"