[PATCH for v4.17] cec: fix smatch error

[Hans Verkuil]

drivers/media/cec/cec-pin-error-inj.c:231
cec_pin_error_inj_parse_line() error: uninitialized symbol 'pos'.

The tx-add-bytes command didn't check for the presence of an argument, and
also didn't check that it was > 0.

This should fix this error.

Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
---
diff --git a/drivers/media/cec/cec-pin-error-inj.c 
b/drivers/media/cec/cec-pin-error-inj.c
index aaa899a175ce..7132a2758bd3 100644
--- a/drivers/media/cec/cec-pin-error-inj.c
+++ b/drivers/media/cec/cec-pin-error-inj.c
@@ -203,16 +203,18 @@ bool cec_pin_error_inj_parse_line(struct cec_adapter 
*adap, char *line)
                mode_mask = CEC_ERROR_INJ_MODE_MASK << mode_offset;
                arg_idx = cec_error_inj_cmds[i].arg_idx;

-               if (mode_offset == CEC_ERROR_INJ_RX_ARB_LOST_OFFSET ||
-                   mode_offset == CEC_ERROR_INJ_TX_ADD_BYTES_OFFSET)
-                       is_bit_pos = false;
-
                if (mode_offset == CEC_ERROR_INJ_RX_ARB_LOST_OFFSET) {
                        if (has_op)
                                return false;
                        if (!has_pos)
                                pos = 0x0f;
+                       is_bit_pos = false;
+               } else if (mode_offset == CEC_ERROR_INJ_TX_ADD_BYTES_OFFSET) {
+                       if (!has_pos || !pos)
+                               return false;
+                       is_bit_pos = false;
                }
+
                if (arg_idx >= 0 && is_bit_pos) {
                        if (!has_pos || pos >= 160)
                                return false;