Uninitialized pointer read

Incorrect values could be read from, or even written to, an arbitrary memory location, causing incorrect computations. Reads an uninitialized pointer or its target
/src/support/err.c:229: UNINIT 121248 Declaring variable "ap_copy" without initializer.
/src/support/err.c:400: UNINIT 121248 Using uninitialized value "ap_copy" when calling "__wt_vsnprintf_len_set".