fix: remove unnecessary variable assignment in compute function

Author: rajanarahul93

lib/node_modules/@stdlib/math/base/special/gammaincinv/src/main.c

@@ -735,7 +735,6 @@ static double compute( const double a, const double p, const double q ) {
                 x0 = x0 - L + ( b*r*evalpoly( CK, 5, r ) );
             } else {
                 r = 1.0 / x0;
-                L2 = L * L;
                 double ck = L - 1.0;
                 t = L - (b*r*ck);
                 if ( t < x0 ) {