qrexec-lib: convert tabs to spaces

- Fix compile error on gcc 6 (-Werror=misleading-indentation)
- Follow coding style: https://www.qubes-os.org/doc/coding-style/

qrexec-lib/unpack.c

@@ -94,9 +94,9 @@ void fix_times_and_perms(struct file_header *untrusted_hdr,
         const char *untrusted_name)
 {
     struct timeval times[2] =
-	    { {untrusted_hdr->atime, untrusted_hdr->atime_nsec / 1000},
-	    {untrusted_hdr->mtime,
-	     untrusted_hdr->mtime_nsec / 1000}
+    { 
+        {untrusted_hdr->atime, untrusted_hdr->atime_nsec / 1000},
+        {untrusted_hdr->mtime, untrusted_hdr->mtime_nsec / 1000}
     };
     if (chmod(untrusted_name, untrusted_hdr->mode & 07777))  /* safe because of chroot */
         do_exit(errno, untrusted_name);

qrexec-lib/write-stdin.c

@@ -59,8 +59,8 @@ int flush_client_data(int fd, struct buffer *buffer)
 }
 
 /*
-Write "len" bytes from "data" to "fd". If not all written, buffer the rest
-to "buffer".
+ * Write "len" bytes from "data" to "fd". If not all written, buffer the rest
+ * to "buffer".
  */
 int write_stdin(int fd, const char *data, int len, struct buffer *buffer)
 {
@@ -92,9 +92,9 @@ int write_stdin(int fd, const char *data, int len, struct buffer *buffer)
 }
 
 /* 
-Data feed process has exited, so we need to clear all control structures for 
-the client. However, if we have buffered data for the client (which is rare btw),
-fire&forget a separate process to flush them.
+ * Data feed process has exited, so we need to clear all control structures for 
+ * the client. However, if we have buffered data for the client (which is rare btw),
+ * fire&forget a separate process to flush them.
  */
 int fork_and_flush_stdin(int fd, struct buffer *buffer)
 {