*: use "can't" instead of "cannot"

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/udhcp/arpping.c b/networking/udhcp/arpping.c
index 48158fc..3df0f39 100644
--- a/networking/udhcp/arpping.c
+++ b/networking/udhcp/arpping.c
@@ -57,7 +57,7 @@
 	}
 
 	if (setsockopt_broadcast(s) == -1) {
-		bb_perror_msg("cannot enable bcast on raw socket");
+		bb_perror_msg("can't enable bcast on raw socket");
 		goto ret;
 	}
 
diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index 23292a5..dc5d9ff 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -77,7 +77,7 @@
 
 	/* Create pidfile */
 	write_pidfile(server_config.pidfile);
-	/* if (!..) bb_perror_msg("cannot create pidfile %s", pidfile); */
+	/* if (!..) bb_perror_msg("can't create pidfile %s", pidfile); */
 
 	bb_info_msg("%s (v"BB_VER") started", applet_name);
 
diff --git a/networking/udhcp/options.c b/networking/udhcp/options.c
index 38f9919..10ec459 100644
--- a/networking/udhcp/options.c
+++ b/networking/udhcp/options.c
@@ -255,6 +255,6 @@
 		}
 	}
 
-	bb_error_msg("cannot add option 0x%02x", code);
+	bb_error_msg("can't add option 0x%02x", code);
 	return 0;
 }
diff --git a/networking/udhcp/signalpipe.c b/networking/udhcp/signalpipe.c
index a025bd8..c181e0e 100644
--- a/networking/udhcp/signalpipe.c
+++ b/networking/udhcp/signalpipe.c
@@ -29,7 +29,7 @@
 {
 	unsigned char ch = sig; /* use char, avoid dealing with partial writes */
 	if (write(signal_pipe.wr, &ch, 1) != 1)
-		bb_perror_msg("cannot send signal");
+		bb_perror_msg("can't send signal");
 }