script: fix compiler warnings [-Wmaybe-uninitialized]

script: fix compiler warnings [-Wmaybe-uninitialized]

term-utils/script.c: In function 'log_close.part.0.isra':
term-utils/script.c:306:3: warning: 'now.tv_usec' may be used uninitialized in this function [-Wmaybe-uninitialized]
term-utils/script.c:303:18: note: 'now.tv_usec' was declared here
term-utils/script.c:306:3: warning: 'now.tv_sec' may be used uninitialized in this function [-Wmaybe-uninitialized]
term-utils/script.c:303:18: note: 'now.tv_sec' was declared here

Signed-off-by: Karel Zak <kzak@redhat.com>