Fix Coverity errors in driver/xen_events.c

Coverity ID 1237221: Uninitialized scalar variable (UNINIT)11. uninit_use: Using uninitialized value out_access.
Coverity ID 1237219: Resource leak (RESOURCE_LEAK)10. leaked_storage: Variable xe going out of scope leaks the storage it points to
Kdbg search resource leak fixes

Coverity ID 1237214: Resource leak (RESOURCE_LEAK)10. leaked_storage: Variable f going out of scope leaks the storage it points to.
Coverity ID 1237215: Resource leak (RESOURCE_LEAK)10. leaked_storage: Variable bm64 going out of scope leaks the storage it points to.
Coverity ID 1237218: Resource leak (RESOURCE_LEAK)8. leaked_storage: Variable bm going out of scope leaks the storage it points to.
Coverity fixes in core.c

CID 703181 (#1 of 1): Dereference before null check (REVERSE_INULL)check_after_deref: Null-checking vmi suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
CID 1237203 (#1 of 1): Unchecked return value (CHECKED_RETURN)3. check_return: Calling arch_init without checking return value (as is done elsewhere 7 out of 8 times)
Coverity fixes in arch/intel.c

CID 703167 (#1 of 1): Missing parentheses (CONSTANT_EXPRESSION_RESULT)missing_parentheses: !instance->os_type == VMI_OS_WINDOWS is always false regardless of the values of its operands. This occurs as the logical operand of if.
CID 1237204 (#1 of 1): Unchecked return value (CHECKED_RETURN)2. check_return: Calling vmi_read_64_pa without checking return value (as is done elsewhere 14 out of 15 times).
CID 1237206 (#1 of 1): Logically dead code (DEADCODE)dead_error_line: Execution cannot reach this statement: return;.
Coverity fix in driver/xen.c

CID 703184 (#1 of 1): Dereference before null check (REVERSE_INULL)check_after_deref: Null-checking name suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
Merge branch 'coverity_fixes2' of github.com:tklengyel/libvmi into staging
Merge branch 'coverity_fixes3' of github.com:tklengyel/libvmi into staging
Merge branch 'coverity_fixes4' of github.com:tklengyel/libvmi into staging
Merge branch 'coverity_fixes5' of github.com:tklengyel/libvmi into staging
Merge branch 'coverity_fixes6' of github.com:tklengyel/libvmi into staging