Close the DL handle when check() or init() fail
Close the DL handle when check() or init() fail

Otherwise that handle remains open and may cause weird issues later.

vpodzime/libblockdev,vpodzime/libblockdev,rhinstaller/libblockdev,atodorov/libblockdev,atodorov/libblockdev,rhinstaller/libblockdev,vpodzime/libblockdev,atodorov/libblockdev,rhinstaller/libblockdev