Automerge: [libc][test] Remove more unused nan variables (#155925)

These are redefined/shadowed by the if constexpr (FPBits::FRACTION_LEN -
1 >= 5) case below.

Added by llvm/llvm-project#155569. I missed
these ones in #155894.

Author: rupprecht

libc/test/src/math/smoke/TotalOrderMagTest.h

@@ -106,12 +106,6 @@ class TotalOrderMagTestTemplate : public LIBC_NAMESPACE::testing::FEnvSafeTest {
   }
 
   void testNaNPayloads(TotalOrderMagFunc func) {
-
-    T qnan_0x15 = FPBits::quiet_nan(Sign::POS, 0x15).get_val();
-    T neg_qnan_0x15 = FPBits::quiet_nan(Sign::NEG, 0x15).get_val();
-    T snan_0x15 = FPBits::signaling_nan(Sign::POS, 0x15).get_val();
-    T neg_snan_0x15 = FPBits::signaling_nan(Sign::NEG, 0x15).get_val();
-
     EXPECT_TRUE(funcWrapper(func, aNaN, aNaN));
     EXPECT_TRUE(funcWrapper(func, sNaN, sNaN));