[PATCH] Really *do* nothing in while loop

A deflate loop in sha1_file.c would have /* nothing */ as its
body, but the semicolon was missing, so the next command was run.
Fortunately the loop went through exactly once so it didn't trigger
an actual bug so far.

Signed-Off-by: Thomas Glanzmann <sithglan@stud.uni-erlangen.de>
Signed-off-by: Petr Baudis <pasky@ucw.cz>