examples:winexe: Fully initialize EXPLICIT_ACCESS

examples:winexe: Fully initialize EXPLICIT_ACCESS

"Error: UNINIT (CWE-457):
samba-4.20.0rc2/examples/winexe/winexesvc.c:60: var_decl: Declaring variable ""ea"" without initializer.
samba-4.20.0rc2/examples/winexe/winexesvc.c:86: uninit_use_in_call: Using uninitialized value ""ea"". Field ""ea.Trustee.pMultipleTrustee"" is uninitialized when calling ""SetEntriesInAclA"".
   84|
   85|   	/* Create a new ACL that contains the new ACEs */
   86|-> 	dwRes = SetEntriesInAcl(1, &ea, NULL, &pACL);
   87|   	if (ERROR_SUCCESS != dwRes) {
   88|   		dbg(""SetEntriesInAcl Error %lu\n"", GetLastError());"

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Alexander Bokovoy <ab@samba.org>