nilfs2: fix typo "numer" -> "number" in alloc.c
nilfs2: fix typo "numer" -> "number" in alloc.c

Fixes the typo found in a warning message of a persistent object
allocator function.

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

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