shell: Consume all input data

A transport may receive multiple bytes of data between shell_thread
wakeups, but state_collect is only called once per wakeup.  So it must
process all data, and only return when all data from the transport has
been consumed.  This is mostly handled correctly, but there were two
places where state_collect would return early instead.

Signed-off-by: Jim Paris <jim@jtan.com>

Author: jimparis

subsys/shell/shell.c

@@ -882,7 +882,7 @@ static void state_collect(const struct shell *shell)
 				 * on received NL.
 				 */
 				state_set(shell, SHELL_STATE_ACTIVE);
-				return;
+				continue;
 			}
 
 			switch (data) {
@@ -950,7 +950,7 @@ static void state_collect(const struct shell *shell)
 			receive_state_change(shell, SHELL_RECEIVE_DEFAULT);
 
 			if (!flag_echo_get(shell)) {
-				return;
+				continue;
 			}
 
 			switch (data) {