lib/ts_bm.c: remove redundant store to variable consumed after addition

There is no need to store the result of the addition back to variable
consumed after the addition.  The store is redundant, replace += with just
+

Cleans up clang scan build warning: lib/ts_bm.c:83:11: warning: Although
the value stored to 'consumed' is used in the enclosing expression, the
value is never actually read from 'consumed' [deadcode.DeadStores]

Link: https://lkml.kernel.org/r/20220704215325.600993-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/ts_bm.c

@@ -80,7 +80,7 @@ static unsigned int bm_find(struct ts_config *conf, struct ts_state *state)
 
 			/* London calling... */
 			DEBUGP("found!\n");
-			return consumed += (shift-(bm->patlen-1));
+			return consumed + (shift-(bm->patlen-1));
 
 next:			bs = bm->bad_shift[text[shift-i]];