Fix remaining static analysis warnings

Fix or suppress the remaining warnings generated by static analysis.
This is a necessary step before we can incorporate static analysis into
CI. Where possible, I've preferred to modify the code itself instead of
just disabling the warning with a magic comment, so that if we decide to
use different static analysis tools in the future we will be covered
against them raising similar warnings.

src/jemalloc.c

@@ -991,7 +991,8 @@ obtain_malloc_conf(unsigned which_source, char buf[PATH_MAX + 1]) {
 		 * Each source should only be read once, to minimize # of
 		 * syscalls on init.
 		 */
-		assert(read_source++ == which_source);
+		assert(read_source == which_source);
+		read_source++;
 	}
 	assert(which_source < MALLOC_CONF_NSOURCES);