block: Make bdrv_is_whitelisted() public

We'll use a separate source file for image creation, and we need to
check there whether the requested driver is whitelisted.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

block.c

@@ -370,7 +370,7 @@ BlockDriver *bdrv_find_format(const char *format_name)
     return bdrv_do_find_format(format_name);
 }
 
-static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
+int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
 {
     static const char *whitelist_rw[] = {
         CONFIG_BDRV_RW_WHITELIST

include/block/block.h

@@ -226,6 +226,7 @@ char *bdrv_perm_names(uint64_t perm);
 void bdrv_init(void);
 void bdrv_init_with_whitelist(void);
 bool bdrv_uses_whitelist(void);
+int bdrv_is_whitelisted(BlockDriver *drv, bool read_only);
 BlockDriver *bdrv_find_protocol(const char *filename,
                                 bool allow_protocol_prefix,
                                 Error **errp);