module: Fix ERRORs reported by checkpatch.pl

Checkpatch reports following errors:

ERROR: do not use assignment in if condition
+	if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {

ERROR: do not use assignment in if condition
+		if ((mod = find_module_all(name, colon - name, false)) != NULL)

ERROR: do not use assignment in if condition
+			if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)

ERROR: do not initialise globals to 0
+int modules_disabled = 0;

Fix them.

The following one has to remain, because the condition has to be evaluated
multiple times by the macro wait_event_interruptible_timeout().

ERROR: do not use assignment in if condition
+	if (wait_event_interruptible_timeout(module_wq,

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>