Fix optstring for showmap -f am: 42ab62c2d6 am: 0bdff28363 am: a93cdc0354

Original change: https://android-review.googlesource.com/c/platform/system/memory/libmeminfo/+/2193402

Change-Id: I2e5fbf0c1fd2c4d679f9a340a0c2f7d767411761
Signed-off-by: Automerger Merge Worker <[email protected]>