*: intrduce and use safe_gethostname. By Tito <farmatito AT tiscali.it>

safe_gethostname                                       -      48     +48
glob3                                                 35      37      +2
timestamp_and_log                                    314     315      +1
udhcp_send_kernel_packet                             234     231      -3
scan_tree                                            275     271      -4
passwd_main                                         1074    1070      -4
print_login_prompt                                    68      58     -10
obscure                                              392     377     -15
syslogd_main                                         882     866     -16
print_login_issue                                    516     478     -38
hostname_main                                        278     223     -55
parse_and_put_prompt                                 825     756     -69
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/9 up/down: 51/-214)          Total: -163 bytes
   text    data     bss     dec     hex filename
 798791     728    7484  807003   c505b busybox_old
 798631     728    7484  806843   c4fbb busybox_unstripped

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 9aab637..c6aa45c 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -1203,11 +1203,7 @@
 					break;
 #endif
 				case 'h':
-					pbuf = free_me = xzalloc(256);
-					if (gethostname(pbuf, 255) < 0) {
-						pbuf[0] = '?';
-						pbuf[1] = '\0';
-					}
+					pbuf = free_me = safe_gethostname();
 					*strchrnul(pbuf, '.') = '\0';
 					break;
 				case '$':