qcacmn: Fix Integer Overflow Leading to Buffer Overflow

wmi_buf_alloc() API expects length to be passed of type
uint16_t. However, the callers pass uint32_t to it.
This might result in overflow and illegal memory access
thereafter. The fix is to modify the API signature accordingly.

Change-Id: If09da4978d421269b884f7d3c933c49c81651475
CRs-Fixed: 2218346
diff --git a/wmi_unified_api.h b/wmi_unified_api.h
index 680226a..f8cf143 100644
--- a/wmi_unified_api.h
+++ b/wmi_unified_api.h
@@ -195,10 +195,10 @@
 #ifdef NBUF_MEMORY_DEBUG
 #define wmi_buf_alloc(h, l) wmi_buf_alloc_debug(h, l, __FILE__, __LINE__)
 wmi_buf_t
-wmi_buf_alloc_debug(wmi_unified_t wmi_handle, uint16_t len,
+wmi_buf_alloc_debug(wmi_unified_t wmi_handle, uint32_t len,
 		    uint8_t *file_name, uint32_t line_num);
 #else
-wmi_buf_t wmi_buf_alloc(wmi_unified_t wmi_handle, uint16_t len);
+wmi_buf_t wmi_buf_alloc(wmi_unified_t wmi_handle, uint32_t len);
 #endif
 
 /**