Fix some compile warnings on RHEL5

- returned char not needed to be explicitly const
- warn if pipe() fails in clvmd (more fixes here needed for error paths...)
- assign (and ignore) read() output in drain buffer

daemons/clvmd/clvmd.c

@@ -1007,7 +1007,10 @@ static void be_daemon(int timeout)
 		exit(3);
 	}
 
-	pipe(child_pipe);
+	if (pipe(child_pipe)) {
+		perror("Error creating pipe");
+		exit(3);
+	}
 
 	switch (fork()) {
 	case -1:
@@ -1254,7 +1257,9 @@ static int read_from_local_sock(struct local_client *thisfd)
 		}
 
 		/* Create a pipe and add the reading end to our FD list */
-		pipe(comms_pipe);
+		if (pipe(comms_pipe))
+			DEBUGLOG("creating pipe failed: %s\n", strerror(errno));
+		
 		newfd = malloc(sizeof(struct local_client));
 		if (!newfd) {
 			struct clvm_header reply;

daemons/dmeventd/libdevmapper-event.c

@@ -309,7 +309,7 @@ static int _daemon_write(struct dm_event_fifos *fifos,
 		}
 		if (ret == 0)
 			break;
-		read(fifos->server, drainbuf, 127);
+		ret = read(fifos->server, drainbuf, 127);
 	}
 
 	while (bytes < size) {

lib/display/display.c

@@ -131,7 +131,7 @@ uint64_t units_to_bytes(const char *units, char *unit_type)
 		return v * multiplier;
 }
 
-const char alloc_policy_char(alloc_policy_t alloc)
+char alloc_policy_char(alloc_policy_t alloc)
 {
 	int i;
 

lib/display/display.h

@@ -57,7 +57,7 @@ void display_segtypes(const struct cmd_context *cmd);
  * Allocation policy display conversion routines.
  */
 const char *get_alloc_string(alloc_policy_t alloc);
-const char alloc_policy_char(alloc_policy_t alloc);
+char alloc_policy_char(alloc_policy_t alloc);
 alloc_policy_t get_alloc_from_string(const char *str);
 
 char yes_no_prompt(const char *prompt, ...) __attribute__ ((format(printf, 1, 2)));