nilfs2: fix discrepancy in use of static specifier
nilfs2: fix discrepancy in use of static specifier

Two segbuf functions, nilfs_segbuf_write and nilfs_segbuf_wait, are
declared with the static storage class specifier, but their
implementations are not.

This fixes the discrepancy.

Signed-off-by: Ryusuke Konishi <f414f2bdd839fdc054376382fa67e9bc2fbf206f@lab.ntt.co.jp>

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