PatchTrackBase: fix null pointer dereference issue

cblk will be released when the function isTrackAllowed_l returns false, so when creating PatchTrackBase we should check whether the cblk is released to prevent null pointer dereferencing issue.

Test: make libaudioflinger
Bug: 290325983

Change-Id: I2a61b5b4f7777528cd4f8f2aa80dfec113bfce2e
Signed-off-by: gaoxiupei <gaoxiupei@xiaomi.corp-partner.google.com>