mksdfuse: add a file checking function for mkfs
mksdfuse: add a file checking function for mkfs

This patch adds a function which waits for a file creation
to avoid failuire due to mounting is in progress.
mkfs can be failed to find a loop device while mounting is
in progress.

Report&Verified by taeksu.shin@samsung.com

Change-Id: Ic7296663e62e2abdab9cd6cb2bdc624d4604ff14
Signed-off-by: Dongil Park <d9897b35705a73a11588d0b215caeac05e1d6e8f@samsung.com>

SamsungARTIK/build-artik