smartmontools: fix dependency declaration by f5f49e4

Fix the dependency declaration by removing the unnecessary/illegal
commas:

>  WARNING: Makefile 'package/feeds/packages/smartmontools/Makefile' has a dependency on 'smartd,', which does not exist
>  WARNING: Makefile 'package/feeds/packages/smartmontools/Makefile' has a dependency on 'nail,', which does not exist
>  tmp/.config-package.in:153368:warning: ignoring unsupported character ','
>  tmp/.config-package.in:153373:warning: ignoring unsupported character ','

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

utils/smartmontools/Makefile

@@ -72,7 +72,7 @@ define Package/smartd-mail
   $(call Package/smartmontools/Default)
   TITLE+= Email notifications
   PKGARCH=all
-  DEPENDS+= +smartd, +nail, +msmtp-mta
+  DEPENDS+= +smartd +nail +msmtp-mta
 endef
 
 define Package/smartd-mail/description