staging: rtlwifi: Remove unnecessary parentheses

Challenge suggested by coccinelle.
Remove unnecessary parentheses around the right hand side of an
assignment.
Signed-off-by: Payal Kshirsagar <payal.s.kshirsagar.98@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtlwifi/phydm/phydm.c

@@ -1542,7 +1542,7 @@ static void phydm_set_csi_mask_reg(void *dm_void, u32 tone_idx_tmp,
 
 	if (tone_direction == FREQ_POSITIVE) {
 		if (tone_idx_tmp >= (tone_num - 1))
-			tone_idx_tmp = (tone_num - 1);
+			tone_idx_tmp = tone_num - 1;
 
 		byte_offset = (u8)(tone_idx_tmp >> 3);
 		bit_offset = (u8)(tone_idx_tmp & 0x7);