libbb: introduce and use xrealloc_vector

function                                             old     new   delta
xrealloc_vector_helper                                 -      51     +51
create_list                                           84      99     +15
getopt_main                                          690     695      +5
passwd_main                                         1049    1053      +4
get_cached                                            85      89      +4
msh_main                                            1377    1380      +3
add_match                                             42      41      -1
read_lines                                           720     718      -2
grave                                               1068    1066      -2
fill_match_lines                                     143     141      -2
add_to_dirlist                                        67      65      -2
add_input_file                                        49      47      -2
act                                                  252     250      -2
fsck_main                                           2252    2246      -6
man_main                                             765     757      -8
bb_internal_initgroups                               228     220      -8
cut_main                                            1052    1041     -11
add_edge_to_node                                      55      43     -12
dpkg_main                                           3851    3835     -16
ifupdown_main                                       2202    2178     -24
sort_main                                            838     812     -26
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 5/15 up/down: 82/-124)          Total: -42 bytes

1 files changed, 2 insertions, 5 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 3ef47ba71..a46b5d2c4 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -400,11 +400,8 @@ static void free_tab_completion_data(void)
 
 static void add_match(char *matched)
 {
-	int nm = num_matches;
-	int nm1 = nm + 1;
-
-	matches = xrealloc(matches, nm1 * sizeof(char *));
-	matches[nm] = matched;
+	matches = xrealloc_vector(matches, 4, num_matches);
+	matches[num_matches] = matched;
 	num_matches++;
 }