f2fs: read with READ_SYNC when getting dnode page
f2fs: read with READ_SYNC when getting dnode page

The get_node_page_ra tries to:
1. grab or read a target node page for the given nid,
2. then, call ra_node_page to read other adjacent node pages in advance.

So, when we try to read a target node page by #1, we should submit bio with
READ_SYNC instead of READA.
And, in #2, READA should be used.

Signed-off-by: Jaegeuk Kim <20424effba9d4aeeb410130c5f23aa328fa29e09@samsung.com>
Reviewed-by: Namjae Jeon <65d484aa1efdaf0ae258f87a04ed8ec8685cba3e@samsung.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs