fs/fcb: Coverity fix

There was no real problem with the code
356                         loc1.fe_area = fcb_get_prev_area(fcb, loc->fe_area);
>>>     CID 418283:  Code maintainability issues  (UNUSED_VALUE)
>>>     Assigning value "0UL" to "loc1.fe_elem_off" here, but that stored value is overwritten before it can be used.
357                         loc1.fe_elem_off = 0;

This should satisfy coverity

Signed-off-by: Jerzy Kasenberg <jerzy.kasenberg@codecoup.pl>

fs/fcb/src/fcb_getnext.c

@@ -347,15 +347,13 @@ fcb_step(struct fcb *fcb, struct fcb_entry *loc, int previous_error)
             loc1.fe_data_len = 0;
 
             /* Begin of sector ? */
-            if (loc->fe_elem_off == first_entry_offset) {
+            if (loc->fe_elem_off == first_entry_offset || target_ix < 0) {
                 /* Oldest sector, nowhere to go */
                 if (fcb->f_oldest == loc->fe_area) {
                     rc = FCB_ERR_NOVAR;
                 } else {
                     /* Switch to previous sector and find last entry */
                     loc1.fe_area = fcb_get_prev_area(fcb, loc->fe_area);
-                    loc1.fe_elem_off = 0;
-                    loc1.fe_elem_ix = 0;
                 }
             }
             if (rc != FCB_ERR_NOVAR) {
@@ -418,22 +416,22 @@ fcb_step(struct fcb *fcb, struct fcb_entry *loc, int previous_error)
     } else {
         if (loc->fe_area == NULL) {
             loc->fe_area = fcb->f_oldest;
-            loc->fe_elem_off = fcb_start_offset(fcb);
+            loc->fe_elem_off = first_entry_offset;
             loc->fe_elem_ix = 0;
             loc->fe_data_len = 0;
         } else if (previous_error == FCB_ERR_NOVAR) {
             /* If there are more sectors, move to next one */
             if (loc->fe_area != fcb->f_active.fe_area) {
                 loc->fe_area = fcb_getnext_area(fcb, loc->fe_area);
-                loc->fe_elem_off = fcb_start_offset(fcb);
+                loc->fe_elem_off = first_entry_offset;
                 loc->fe_elem_ix = 0;
                 loc->fe_data_len = 0;
             } else {
                 /* No more sectors NOVAR sticks */
                 rc = FCB_ERR_NOVAR;
             }
         } else if (loc->fe_elem_off == 0) {
-            loc->fe_elem_off = fcb_start_offset(fcb);
+            loc->fe_elem_off = first_entry_offset;
             loc->fe_elem_ix = 0;
             loc->fe_data_len = 0;
         } else {