MFC r311227,r311917:

r311227:

seekdir_basic: fix various Coverity issues

Address..

• .. resource leaks of file descriptors and memory
• .. unchecked return values from creat(2), mkdir(2), and telldir(3)
• .. potential NULL derefs after calling readdir(3)

CID: 975255, 975256, 976989, 978989, 978990

r311917:

Fix up r311227

Check for creat returning a value != -1, not a non-zero value

Pointyhat to: ngie
CID: 1368366