test(tty): remove meaningless errno != ENOTTY checks after successful ioctl

L4: CHECK(errno != ENOTTY) and EXPECT_NE(errno, ENOTTY) guards after a
successful ioctl call are meaningless — errno is undefined on success.
The ioctl == 0 check already confirms the call did not fail, making
the errno check redundant.

Removed from both c_unitest and dunitest versions.

Author: DragonOS Dev

user/apps/c_unitest/test_tty_termios.c

@@ -84,20 +84,16 @@ int main(void) {
 
     errno = 0;
     CHECK(ioctl(pts, TCGETA, &tio) == 0, "ioctl TCGETA succeeds");
-    CHECK(errno != ENOTTY, "TCGETA does not return ENOTTY");
 
     tio.c_lflag |= ISIG;
     errno = 0;
     CHECK(ioctl(pts, TCSETA, &tio) == 0, "ioctl TCSETA succeeds");
-    CHECK(errno != ENOTTY, "TCSETA does not return ENOTTY");
 
     errno = 0;
     CHECK(ioctl(pts, TCSETAW, &tio) == 0, "ioctl TCSETAW succeeds");
-    CHECK(errno != ENOTTY, "TCSETAW does not return ENOTTY");
 
     errno = 0;
     CHECK(ioctl(pts, TCSETAF, &tio) == 0, "ioctl TCSETAF succeeds");
-    CHECK(errno != ENOTTY, "TCSETAF does not return ENOTTY");
 
     /* 5. Cross-check: TCGETA reports low 16 bits of what TCGETS reports. */
     struct termios full;

user/apps/tests/dunitest/suites/normal/tty_termios.cc

@@ -170,7 +170,6 @@ TEST(TtyTermios, LegacyTcgeta) {
     errno = 0;
     ASSERT_EQ(ioctl(pty.slave.get(), TCGETA, &tio), 0)
         << "TCGETA should succeed: errno=" << errno << " (" << strerror(errno) << ")";
-    EXPECT_NE(errno, ENOTTY) << "TCGETA must not return ENOTTY";
 }
 
 /* --------------------------------------------------------------------------
@@ -184,17 +183,14 @@ TEST(TtyTermios, LegacyTcsetaFamily) {
     errno = 0;
     EXPECT_EQ(ioctl(pty.slave.get(), TCSETA, &tio), 0)
         << "TCSETA: errno=" << errno << " (" << strerror(errno) << ")";
-    EXPECT_NE(errno, ENOTTY);
 
     errno = 0;
     EXPECT_EQ(ioctl(pty.slave.get(), TCSETAW, &tio), 0)
         << "TCSETAW: errno=" << errno << " (" << strerror(errno) << ")";
-    EXPECT_NE(errno, ENOTTY);
 
     errno = 0;
     EXPECT_EQ(ioctl(pty.slave.get(), TCSETAF, &tio), 0)
         << "TCSETAF: errno=" << errno << " (" << strerror(errno) << ")";
-    EXPECT_NE(errno, ENOTTY);
 }
 
 /* --------------------------------------------------------------------------