fixed bug of ekf_slam.py

[Taka-Kazu]

When I run this script, an error occured.

$python3 ekf_slam.py
ekf_slam.py start!!
New LM
Traceback (most recent call last):
  File "ekf_slam.py", line 266, in <module>
    main()
  File "ekf_slam.py", line 234, in main
    xEst, PEst = ekf_slam(xEst, PEst, ud, z)
  File "ekf_slam.py", line 54, in ekf_slam
    xEst = xEst + (K @ y)
TypeError: ufunc 'matmul' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe''

I found that xEst[2](l. 173) is a 1d-array, so I modified it to be scalar.

[coveralls]

Pull Request Test Coverage Report for Build 800

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• 44 unchanged lines in 4 files lost coverage.
• Overall coverage decreased (-0.5%) to 90.046%

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Files with Coverage Reduction	New Missed Lines	%
PathPlanning/LQRRRTStar/lqr_rrt_star.py	2	76.63%
ArmNavigation/n_joint_arm_to_point_control/n_joint_arm_to_point_control.py	4	93.59%
PathPlanning/ClosedLoopRRTStar/pure_pursuit.py	4	92.97%
PathPlanning/ClosedLoopRRTStar/closed_loop_rrt_star_car.py	34	67.32%

Totals
Change from base Build 797:	-0.5%
Covered Lines:	6785
Relevant Lines:	7535

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💛 - Coveralls

[AtsushiSakai]

@Taka-Kazu Oh, you're right. Thank you!!