Formatting: normalise back to 4-space indentation.

In several pieces of development recently I've run across the
occasional code block in the middle of a function which suddenly
switched to 2-space indent from this code base's usual 4. I decided I
was tired of it, so I ran the whole code base through a re-indenter,
which made a huge mess, and then manually sifted out the changes that
actually made sense from that pass.

Indeed, this caught quite a few large sections with 2-space indent
level, a couple with 8, and a handful of even weirder things like 3
spaces or 12. This commit fixes them all.

import.c

@@ -1249,8 +1249,8 @@ static struct openssh_new_key *load_openssh_new_key(BinarySource *filesrc,
         ret->kdfopts.bcrypt.rounds = get_uint32(opts);
 
         if (get_err(opts)) {
-          errmsg = "failed to parse bcrypt options string";
-          goto error;
+            errmsg = "failed to parse bcrypt options string";
+            goto error;
         }
         break;
       }