editorFindCallback prevents search results navigation

Heyy, while doing the kilo guide, i stumbled across a bug with my editor, for some reason when i press the arrow keys to navigate to the previous and next search result the editor jumped to the next result (as expected) but then imediately jumps back to the previous result where we were originally (preventing search navigation)

To fix this, simply edit the editorFindCallback with the changes...

```c
void editorFindCallback(char *query, int key) {
static int last_match = -1;
static int direction = 1;

// Empty queries reset searching from top
if (strlen(query) == 0) {
last_match = -1;
return;
}

int current;

if (key == '\r' || key == '\x1b') {
last_match = -1;
direction = 1;
return;
} else if (key == ARROW_RIGHT || key == ARROW_DOWN) {
current = last_match+1; // Search from next row
direction = 1;
} else if (key == ARROW_LEFT || key == ARROW_UP) {
current = last_match-1; // Search from previous row
direction = -1;
} else {
direction = 1;
current = last_match; // Keep search on current row with current result to terminate early
}

if (last_match == -1) direction = 1;
int i;
for (i = 0; i < E.numrows; i++) {
// Clamp current
if (current == -1) current = E.numrows - 1;
else if (current == E.numrows) current = 0;

// Immediately search without moving current positon
erow *row = &E.row[current];
char *match = strstr(row->render, query);
if (match) {
last_match = current;
E.cy = current;
E.cx = editorRowRxToCx(row, match - row->render);
E.rowoff = E.numrows;
break;
}

current += direction;
}
}
```