Fix build warnings in recent Rust 1.69.0

[keepsimple1]

Since our minimum Rust version is 1.46.0, these warnings were not reported in CI.

Warning log in Rust 1.69.0:

warning: unnecessary parentheses around index expression
   --> src/lib.rs:712:24
    |
712 |                 ^ (TE1[(temp >> 24)] & 0x000000ff)
    |                        ^          ^
    |
    = note: `#[warn(unused_parens)]` on by default
help: remove these parentheses
    |
712 -                 ^ (TE1[(temp >> 24)] & 0x000000ff)
712 +                 ^ (TE1[temp >> 24] & 0x000000ff)
    |

warning: unnecessary parentheses around index expression
   --> src/lib.rs:738:24
    |
738 |                 ^ (TE1[(temp >> 24)] & 0x000000ff)
    |                        ^          ^
    |
help: remove these parentheses
    |
738 -                 ^ (TE1[(temp >> 24)] & 0x000000ff)
738 +                 ^ (TE1[temp >> 24] & 0x000000ff)
    |

warning: unnecessary parentheses around index expression
   --> src/lib.rs:767:24
    |
767 |                 ^ (TE1[(temp >> 24)] & 0x000000ff)
    |                        ^          ^
    |
help: remove these parentheses
    |
767 -                 ^ (TE1[(temp >> 24)] & 0x000000ff)
767 +                 ^ (TE1[temp >> 24] & 0x000000ff)
    |

warning: unnecessary parentheses around index expression
   --> src/lib.rs:780:24
    |
780 |                 ^ (TE2[(temp >> 24)] & 0xff000000)
    |                        ^          ^
    |
help: remove these parentheses
    |
780 -                 ^ (TE2[(temp >> 24)] & 0xff000000)
780 +                 ^ (TE2[temp >> 24] & 0xff000000)
    |