TFT ST7735: Fixed length bug in drawFastHLine and drawFastVLine

[boul51]

Hi,
I noticed a bug in the ST7735 TFT library in drawFastHLine and drawFastVLine functions. The drawn line is one pixel shorter than it should be. The issue can be reproduced by the following setup function.
Without this commit, the horizontal line (drawn using drawFastHLine) is one pixel shorter than the 45° line.
This is explained by the while (w--) loop preceding the spiwrite call.
With this commit both lines are 2 pixels long.

void setup() {
TFTscreen.begin();
TFTscreen.background(0, 0, 0);
TFTscreen.stroke(255, 0, 0);
TFTscreen.line(0, 0, 1, 1); // 45° line, OK (pixels [0,0] and [1,1] are filled
TFTscreen.line(0, 10, 1, 10); // Horiz. line, NOK (only pixel [0,10] is filled)
}

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