Reapply "Merge pull request ps2dev#687 from uyjulian/iomanx_null_terminate_after_strncpy"

This reverts commit a6cc6d8.

Author: 362053534

iop/system/iomanx/src/iomanX.c

@@ -1059,6 +1059,7 @@ static const char *parsefile(const char *path, iomanX_iop_device_t **p_device, i
 	if ( devname_len > (sizeof(canon) - 1) )
 		return NULL;
 	strncpy(canon, path_trimmed, devname_len);
+	canon[devname_len] = 0;
 	unit = 0;
 	// Search backward for the unit number.
 	while ( isnum(canon[devname_len - 1]) )