logcat: fix -D when using filters

`logcat init:E *:F -D` should print only error messages and above from
init and only fatal messages from other tags.  It should print a
divider (`--------- switch to kernel` for example) when switching to a
new log buffer and printing a message.

However, currently the `--------- switch to kernel` messages are
printed before using the filters, therefore the output is spammed with
extraneous loops of

--------- switch to kernel
--------- switch to main
--------- switch to kernel
--------- switch to main
...

This change fixes this by printing dividers immediately before
printing a log message.

Test: `logcat init:V CompatConfig:V *:F -D` works correctly
Test: `logcat` works correctly
Change-Id: Icf207a126f4f1ef79acc4a12aaf134493529a8e5
1 file changed
tree: 6a8c1be1913e7a9ccf5141a072ad595a1e9d3add
  1. liblog/
  2. logcat/
  3. logd/
  4. logwrapper/
  5. OWNERS
  6. PREUPLOAD.cfg
  7. TEST_MAPPING