eCryptfs: Fix -Wmissing-prototypes warnings
eCryptfs: Fix -Wmissing-prototypes warnings

Mark two inode operation fuctions as static. Fixes warnings when
building with W=1.

Signed-off-by: Tyler Hicks <93eeee00a2beb1fbd6106ad8f59025f171ca91c6@canonical.com>

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