Resolve gcc 4.9.0 20140507 warnings about uninitialized 'ptr' when
using -Wmaybe-uninitialized. The first two cases appears appear
to be legitimate but not the second two. In general this is a
good practice so they are all initialized.
Signed-off-by: Marcel Huber <marcelhuberfoo@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2345